Figure 3From: Ordered arrays of nanoporous silicon nanopillars and silicon nanopillars with nanoporous shellsSEM images of nanopillars formed from the highly doped Si after 10-min etching. In (a) λ1, (b) λ2, (c) λ3, and (d) λ4 solutions. The distance mark in (d) indicates the range of the nanoporous base layer under the Au film and nanopillars.Back to article page